Isokinetic training and Russian current stimulation have been advertised to increase muscle strength. So, the purpose of this study was to compare between unilateral isokinetic concentric training and Russian current stimulation on the quadriceps strength of ipsilateral and contralateral limbs. Sixty healthy male subjects were randomly assigned into 3 equal groups; Isokinetic group; received isokinetic concentric training. Russian group; received Russian current stimulation, and control group: did not receive any training program. Isokinetic and Russian groups trained for 4 weeks, 3 session/week on the dominant quadriceps femoris muscle. Biodex Multi-joint System 3, Biodex, Shirley, NY, used to measure the isokinetic concentric peak torque/body weight before and after 4 weeks training for all groups at angular velocity 30°/s. For contralateral and ipsilateral quadriceps strength there was significant increase in the quadriceps strength of isokinetic and Russain group (p= 0.000). However, there was no significant increase in the quadriceps strength of control group (p= 0.214, 0.061) respectively. There was no significant difference between isokinetic and Russian group for the value of increasing of the quadriceps strength (p= 0.391, 0.579) respectively. The percent of improvement of ipsilateral side was significantly higher than the improvement of contralateral side for isokinetic and Russian group (p= 0.004, 0.006) respectively. So, Isokinetic training and Russian current stimulation have equal level of effectiveness in improving the concentric strength of the contralateral and ipsilateral quadriceps muscle. In spite of, the improvement of ipsilateral side was higher than that of the contralateral side.